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Basics ⬇

Author: JulieChuan, MD, FAAFP, CAQSM

Description

  • Transverse fractures occur from a bending force.
  • Spiral fractures occur from torsion.
  • Oblique fractures occur from bending and torsion and may have an associated butterfly fragment.
  • Proximal or distal comminuted fractures occur from compressive forces.
ALERT

Spiral fractures in children are concerning for child abuse.

Epidemiology

  • Bimodal distribution in the 3rd and 7th decades
  • 3rd decade male predominance owing to sports and vehicular trauma
  • 7th decade female predominance owing to simple falls (1)[B]
  • 90% are due to trauma.
  • Risk factors include trauma, increasing age, and osteoporosis.
  • Types:
    • Midshaft: 60%
    • Proximal shaft: 25%
    • Distal shaft: 10% (1)[B]

Diagnosis ⬆ ⬇

  • History and physical examination with special attention to a thorough neurovascular and skin examination
  • Consider associated injuries such as ipsilateral shoulder, elbow, wrist, or hand fractures or dislocations.
  • Diagnosis is confirmed by x-ray.
  • Prehospital:
    • Immobilize with sling and swath for transport.
    • Evaluate for open fracture.
    • Evaluate for distal neurologic and vascular deficit.
    • Rapid transport in presence of neurologic or vascular deficits

History

  • History of fall: Simple trip and fall, a low-impact force, is often associated with older (70+ yr), osteoporotic women.
  • Collision or direct blow: higher impact, occurring more commonly in younger men
  • Pain after throwing or pitching
  • History of malignancy
  • Consider as pathologic fractures any humerus fracture produced by low-energy mechanism; the humerus can be a common site of metastatic disease.
ALERT
  • “Falls” in toddlers or infants are concerning for abuse.
  • Check for other bruises and injuries suggesting abuse.
  • Examine the elbow in children who are guarding their arm.
  • Elbow dislocations are more common in toddlers (nursemaid’s elbow).
  • Supracondylar fractures are more common in children when they sustain a fall.

Physical Exam

  • Pain and swelling over the area of the humeral shaft
  • Shortening, deformity, or decreased mobility
  • Crepitus on gentle passive range of motion (ROM)
  • Neurologic deficit (2)[C],(3)[B]:
    • Radial nerve is most commonly injured, occurring in 15% of humeral shaft fractures:
      • It is tethered down and emerges through the intermuscular septum at the middle to distal shaft.
      • Injury will affect active extension in the wrist, hand, and fingers.
      • Motor function can be tested by giving the “thumbs-up” sign.
      • Occurs most frequently in middle and distal shaft fractures and spiral fractures
      • Usually a neurapraxia or axonotmesis (perineurium and epineurium intact)
    • Ulnar nerve injury will affect finger abduction (spreading the fingers apart).
    • Median nerve injury will affect thumb opposition (thumb and small finger pinch), loss of sensation on the palmar surface of the thumb, and the index and middle fingers.
    • Injury to the largest branch of the median nerve is the anterior interosseous nerve. Damage will result in loss of hand and finger flexion.
  • Vascular injury: presenting as decreased pulse, slow distal capillary refill, and/or cool extremity:
  • Open fracture: If the skin is disrupted over the site of the fracture, there is a high risk of infection and need for surgical evaluation.

Differential Diagnosis

  • Bone contusion
  • Muscle contusion: primarily the biceps, triceps, or deltoid
  • Hematoma
  • Tendon rupture: primarily the biceps
  • Neurapraxia: primarily the radial nerve
  • Abscess

Diagnostic Tests & Interpretation

  • Anteroposterior (AP) and lateral views of the entire humerus are mandatory to assess for fracture pattern:
    • Displacement, including angulation and shortening type of fracture: transverse, spiral, oblique
    • Location of the fracture on the humeral shaft in relation to muscle attachments
    • Number of fracture segments (butterfly fragments) and comminution
  • Include shoulder and elbow views to exclude associated joint involvement.
  • The AO/ASIF system defines humeral shaft fractures as follows (3)[B]:
    • Type A: simple fractures:
      • A1: simple spiral
      • A2: simple short oblique
      • A3: simple transverse
    • Type B: wedge fractures:
      • B1: spiral wedge
      • B2: bending wedge
      • B3: fragmented wedge
    • Type C: complex pattern fractures:
      • C1: complex spiral
      • C2: segmental fracture
      • C3: irregular comminuted fracture
  • Pathologic findings:
    • Pathologic fractures of the humeral shaft are associated with the following malignancies (1)[B]:
      • Women:
        • Breast 40%
        • Myeloma 23%
        • Lung 9%
        • Kidney 9%
      • Men:
        • Prostate 33%
        • Kidney 25%
        • Myeloma 8%
        • Lung 8%

Treatment ⬆ ⬇

General Measures

  • These fractures usually do not require elaborate reduction or immobilization.
  • Fractures without neurovascular compromise can be treated conservatively; see immobilization options below.
  • Immobilize for 4 to 6 wk until clinically and radiographically healed.
  • Prehospital:
    • With the introduction of functional (Sarmiento) bracing, conservative treatment has become more popular and can be managed in the office.
    • Conservative care can be undertaken with 80% healing rates for adults with low to moderate functional demands. The degree of displacement accepted in these studies was up to 20 degrees and 2 cm of shortening:
      • Fractures can displace further after injury owing to contraction of the surrounding muscles (see below).
      • No randomized, controlled trials support these recommendations, so they are class C recommendations.
    • Open fractures or fractures associated with neurovascular compromise require immediate orthopedic consultation.
    • Children remodel well and usually are able to compensate with overgrowth for fractures up to 1.5 cm shortening and 20 degrees of angulation.
    • Anyone with high functional demands such as elite athletes, mechanics, and carpenters should be considered for surgical fixation for optimal anatomic alignment.
    • Of the nonunions, 90% ultimately heal with surgical intervention.
    • The carrying angle (valgus angle at the elbow when the arm is fully extended) is most often affected in displaced humeral shaft fractures (4)[C].

Medication

  • Immobilization: Immobilize to limit movement at the site of the fracture, which is one of the most effective methods of pain control.
  • Ice: Icing the fracture site intermittently (15 min QID) for the first few days will reduce swelling and help to control pain.
  • Elevation: After immobilization, try to elevate the arm above the level of the heart as much as possible to minimize swelling.
  • Analgesic medications:
    • Narcotic analgesics: initially may be needed for adequate pain control
    • Nonnarcotic analgesics: After the fracture stabilizes (about 1 wk), nonsteroidal anti-inflammatory drugs (NSAIDs) and/or acetaminophen should provide sufficient pain relief.

Issues for Referral

Surgical indications (4)[B]:

  • Unacceptable alignment after closed reduction
  • Radial nerve palsy at any evaluation, including after closed reduction
  • Multisite trauma
  • Open or segmental fractures
  • Floating elbow: occurs when there is a fracture above and below the elbow and is considered an “unstable” injury
  • Ipsilateral arm injuries
  • Pathologic fractures
  • Fracture with significant gap between segments usually represents muscle or fat separating the bone fragments and is unlikely to heal.
  • Vascular injury: Refer for urgent vascular surgery evaluation.

Additional Therapies

Consider displacing forces of the contracted muscles around the site of fracture when immobilizing the injury:

  • Supraspinatus, infraspinatus, and teres minor externally rotate the humeral head.
  • Subscapularis internally rotates the humeral head.
  • Pectoralis pulls fragments toward the chest (medially) and forward (anteriorly).
  • Latissimus and teres major pull fragments inward toward the chest.
  • Deltoid displaces the fracture outward (abducts) away from the chest.

Surgery/Other Procedures

  • Surgical options:
    • Intermedullary nailing
    • External fixation
    • Plate fixation
  • Immobilization options for conservative management (3)[C]:
    • Sling immobilization: best for nondisplaced fractures that do not need distraction but can predispose to further shortening
    • Sugar-tong, coaptation, or U-shaped splint: best for limitation of transverse fracture displacement; limits shoulder and elbow motion, predisposing to stiffness after prolonged immobilization
    • Hanging cast: better for displaced or comminuted fractures needing distraction:
      • Elbow is placed in 90 degrees of flexion and the forearm in a neutral position.
      • Needs closer follow-up after injury to evaluate for signs of compartment syndrome
      • Cannot keep arm elevated to minimize swelling because gravity aids with distraction of the fracture
    • Functional bracing:
      • Preferred definitive treatment of transverse humerus shaft fractures and most other midshaft fractures
      • Allows for elbow mobility and earlier ROM; applied after initial swelling subsides and fracture starts to stabilize, usually 2 wk after injury
    • Always repeat the vascular and neurologic examination after splint or cast application.
  • Surgical treatment:
    • Benefits:
      • More predictable alignment
      • Immediate stability
    • Risks:
      • Infection
      • Nerve and vascular injury
      • Nonunion
      • Anesthesia risks
  • Conservative treatment (5)[B]:
    • Benefits:
      • Functional bracing usually allows for full or nearly full shoulder and elbow mobility.
      • Less infection and neurovascular injury risk
    • Risks:
      • Skin breakdown
      • Angular or translational malalignment/deformity
      • Nonunion (higher in simple fractures or type 1)
      • Shoulder or elbow stiffness

Ongoing Care ⬆ ⬇

  • Immobilize until clinical healing and pain free, with bony callus on radiographs, usually 4 to 6 wk.
  • Begin pendulum exercises within 1 wk.
  • Start passive ROM after 2 wk to minimize shoulder and elbow stiffness.

Follow-up Recommendations

Nonunion risk factors:

  • Open fracture
  • Segmental (more than two fragments)
  • Transverse (tend to displace into varus owing to displacing forces)
  • Highly comminuted (unable to hold alignment)
  • Associations: smoking, use of NSAIDs
  • Comorbidities: diabetes, hypothyroid, infection, metabolic bone disease (2)[C]

Patient Monitoring

  • Weekly follow-up: initially, every week to assess for displacement of the fracture
  • Every other week: Once the fracture is stable on consecutive radiographs (usually 2 to 3 wk after injury), follow every 2 wk:
    • Once callus is noted on radiograph and no pain on examination, splint can be removed, and shoulder and elbow should be mobilized with gentle ROM exercises.
    • Continue to follow clinically until ROM is restored and healing noted on radiographs (usually 8 to 12 wk).
  • At 12 to 14 wk, if union is not complete clinically and radiographically, consider referral to surgery for intervention.

Patient Education

  • Compartment syndrome signs and symptoms if casted
  • Monitor for new neurologic deficit.
  • Monitor for new vascular deficit.
  • Encourage wrist, hand, and shoulder ROM exercises.
  • Sleep upright (recliner) if in a hanging cast until fracture is stable to minimize displacement.

Complications

  • The most common complications are neurovascular compromise and nonunion.
  • Neurovascular; radial nerve injury
  • Nonunion; occurring in 2–10% of all humeral shaft fractures treated nonoperatively
  • Varus angulation is most common in transverse fractures.
  • Compartment syndrome

Additional Reading ⬆ ⬇

Simon R, Koenigsknecht S. Emergency Orthopedics: the Extremities. 3rd ed. Norwalk, CT: Appleton & Lange; 1995.

References ⬆ ⬇

  1. Ekholm R, Adami J, Tidermark J, et al. Fractures of the shaft of the humerus. An epidemiological study of 401 fractures. J Bone Joint Surg Br. 2006;88(11):1469–1473.
  2. Anglen JO, Archdeacon MT, Cannada LK, et al. Avoiding complications in the treatment of humeral fractures. Instr Course Lect. 2009;58:3–11.
  3. Papasoulis E, Drosos GI, Ververidis AN, et al. Functional bracing of humeral shaft fractures. A review of clinical studies. Injury. 2010;41(7):e21–e27.
  4. Ekholm R, Tidermark J, Törnkvist H, et al. Outcome after closed functional treatment of humeral shaft fractures. J Orthop Trauma. 2006;20(9):591–596.
  5. Jawa A, McCarty P, Doornberg J, et al. Extra-articular distal-third diaphyseal fractures of the humerus. A comparison of functional bracing and plate fixation. J Bone Joint Surg Am. 2006;88(11):2343–2347.

Clinical Pearls ⬆

  • Radial nerve injury is the most common neurovascular injury, occurring in about 15% of humeral shaft fractures.
  • 10 to 20 degrees of angulation and 1 to 2 cm of shortening generally are well tolerated owing to compensated overgrowth and the surrounding muscles.
  • Contraction of the muscles around the humerus can displace the fracture after the initial injury and should be considered when immobilizing the fracture.
  • Consider close weekly follow-up after immobilization to monitor for fracture displacement.